Do disabled buttons still need to be contrast compliant for accessibility?

Very related to this question: Accessible Disabled State but that is about how to style disabled buttons to make them accessibility compliant, but my question is slightly different.

Is it actually an accessibility requirement for disabled features to be contrast compliant?

You are not hiding functionality from visually impaired people by making it grey on grey because the feature is unavailable to everyone, so they are not missing out on features because of this. Yes, it's always better for everything to be contrast compliant, but that might not be relevant here.

The situation is this - we have to disable features of our web application when the system is undergoing scheduled maintenance. Therefore we don't want to remove the buttons altogether because we want the user to know that the feature is only temporarily unavailable. Additional messaging is provided on the page stating that some features are unavailable.

We designed a standard inactive state button (dark grey text on lighter grey button background) but it has come back to us with the concern that it may be failing DDA compliance. However I disagree with that concern for the reasons I state above. Am I mistaken, or is it OK to have grey-on-grey buttons for such situations?

Note: I'm not looking for any alternative solutions (leave that to the linked questions) my query is specifically about whether or not this is an accessibility concern.

Answer

No, it would seem not, as W3C states

1.4.3 Contrast (Minimum): The visual presentation of text and images of text has a contrast ratio of at least 4.5:1, except for the following:

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  Large Text: Large-scale text and images of large-scale text have a contrast ratio of at least 3:1;

  
  


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  Incidental: Text or images of text that are part of an inactive user interface component, that are pure decoration, that are not visible to anyone, or that are part of a picture that contains significant other visual content, have no contrast requirement.

  
  
  


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  Logotypes: Text that is part of a logo or brand name has no contrast requirement.

  
  

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_{My emboldening}